As is known, filling a lavatory flush tank after each flushing operation generates sound vibration which is preferably eliminated or at least reduced.
Various types of flush tank feed devices designed to reduce noise are known.
For example, European Patent Application EP-A-424274 provides for reducing noise by circulating the water in a chamber filled with solid spheroidal bodies. Though fairly effective, this solution still leaves room for further improvement in terms of noise reduction, besides posing manufacturing problems (mainly owing to the necessity of producing and inserting the solid bodies into the chamber).